diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 3a6cb9467f37..4d50edffb0e9 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,22 @@
+2018-02-20  Zalan Bujtas  <zalan@apple.com>
+
+        [RenderTreeBuilder] Move RenderListItem::willBeRemoved() mutation logic to RenderTreeBuilder
+        https://bugs.webkit.org/show_bug.cgi?id=182943
+        <rdar://problem/37689029>
+
+        Reviewed by Antti Koivisto.
+
+        We don't need to destroy the marker in RenderListItem::willBeRemoved(), because it gets deleted
+        in RenderTreeBuilder::removeAndDestroy() together with RenderListItem (as long as the marker is
+        the RenderListItem's descendent). 
+
+        Covered by existing tests.
+
+        * rendering/RenderListItem.cpp:
+        (WebCore::RenderListItem::~RenderListItem):
+        (WebCore::RenderListItem::willBeDestroyed): Deleted.
+        * rendering/RenderListItem.h:
+
 2018-02-20  Chris Dumez  <cdumez@apple.com>
 
         Crash under JSC::JSCell::toNumber(JSC::ExecState*)
diff --git a/Source/WebCore/rendering/RenderListItem.cpp b/Source/WebCore/rendering/RenderListItem.cpp
index 34208d85c17a..76736fcd156f 100644
--- a/Source/WebCore/rendering/RenderListItem.cpp
+++ b/Source/WebCore/rendering/RenderListItem.cpp
@@ -53,13 +53,7 @@ RenderListItem::RenderListItem(Element& element, RenderStyle&& style)
 RenderListItem::~RenderListItem()
 {
     // Do not add any code here. Add it to willBeDestroyed() instead.
-}
-
-void RenderListItem::willBeDestroyed(RenderTreeBuilder& builder)
-{
-    if (m_marker)
-        builder.removeAndDestroy(*m_marker);
-    RenderBlockFlow::willBeDestroyed(builder);
+    ASSERT(!m_marker);
 }
 
 RenderStyle RenderListItem::computeMarkerStyle() const
diff --git a/Source/WebCore/rendering/RenderListItem.h b/Source/WebCore/rendering/RenderListItem.h
index 8398c7b03c55..b701567e8fd8 100644
--- a/Source/WebCore/rendering/RenderListItem.h
+++ b/Source/WebCore/rendering/RenderListItem.h
@@ -62,7 +62,6 @@ class RenderListItem final : public RenderBlockFlow {
     bool isInReversedOrderedList() const;
 
 private:
-    void willBeDestroyed(RenderTreeBuilder&) final;
 
     const char* renderName() const final { return "RenderListItem"; }